Technical Field
The disclosure relates to a diagnostic agent. More particularly, the disclosure relates to a contrast agent or a medical contrast medium used in biomedical imaging.
Description of Related Art
A medical contrast agent is a substance used to enhance the contrast of structures of fluids within the body in medical imaging. Microbubbles contrast agents are used to aid the sonographic detection. The bubbles are composed of tiny amounts of air, nitrogen or perfluorocarbon surrounded by proteins, lipids, or polymer shells. The density on the interface between the gas in the bubble and the surrounding liquid strongly scatters and reflects the ultrasound back to the probe. This process of backscattering gives the liquid with these bubbles a high signal, which can be seen in the resulting image.
Two kinds of microbubbles have been approved by Food and Drug Administration (FDA). One has an albumin shell and octafluoropropane gas core. The other has a lipid/galactose shell and an air core.